How to Understand Depth of Field in Photography
Depth of field is one tool that will make your images more powerful and interesting. It is an artistic focusing choice with a technical foundation.
In this article, I’ll help you understand depth of field and how you can use it in your own photography.
Understanding Depth of Field
Depth of field in photography describes how much of your scene is in focus. Technically, depth of field is the distance between the closest objects in focus and the farthest point of focus. Imagine looking out into a landscape through your camera. Depth of field starts at the first thing you see that’s in focus and extends to the furthest object in focus.
Deep and Shallow DoF
We talk about depth of field in terms of “deep” and “shallow”. Deep DoF is also called “wide” or “large”. Shallow DoF is also called “small” or “narrow”.
Landscape photographers often want the entire scene in focus, from the closest rock to the furthest mountain. This is a “deep” depth of field.
In this image, the waterfall in the background and the rocks in the foreground are both in focus.
Portrait photographers don’t necessarily want the entire scene in focus. If you’re walking around a city taking street portraits, you want the person to be the main focus. A distracting background should be minimized. To do this, you use a shallow depth of field. Your foreground is in focus, but the background is not.
In this image, only the foreground holy man is in focus. The background gives a sense of the environment without distracting from the foreground.
Shallow DoF is a great way to separate your foreground from the background. The background might be uninteresting or distracts attention from your subject. Check out this article about more ways to use shallow depth of field.
It is possible to cleverly combine shallow and deep DoF in one photograph. In this image, the photographer used a smartphone to capture a wide DoF. Then photographed the image using a shallow DoF.
I’ll show you in a minute how to achieve deep and shallow depth of field. But before I do, there’s one more thing you need to know about the focus area.
What is Focus Distribution?
Focus draws the eye. So as a general rule, you should focus on the point of greatest interest. Depth of field tells you how much of the scene will be in focus in front of your focus point and how much of the background will be in focus.
When you select a focus point, focus isn’t equally distributed in front of and behind this point. Often one-third of your focus falls in front of your focus point and the other two-thirds behind it.
Let me give you an example.
I’m going to use an online depth of field calculator to compute how far in front of and behind a subject will be in focus. It might help to open the calculator yourself and follow along.
- I enter my camera body. Sensor size makes a difference to DoF.
- I enter the focal length of my lens. I’m going to use my 50mm lens set at f/11.
- I enter how far away I am from my subject. Let’s say 3 meters (about 10 feet).
The DoF calculator says that the nearest point in focus is 2.14 meters away and the furthest point is 5 meters. This calculator also tells me that 0.86 meters in front of the subject will be in focus (29.97%). Two meters behind my subject (70.03%) will be in focus. This is roughly the one-third versus two-thirds I just mentioned.